1. Field of the Invention
This invention relates to a function-conversion device for the ground monocular telescope and more specifically to a convenient and easy-to-operate function-conversion device for a ground monocular telescope operating on the erecting-prism principle of wherein a reticle removal/mounting, a visibility diaphragm, magnification change or other functions are integrated.
2. Description of the Prior Art
Conventionally, the ground monocular telescopes operating on the erecting-prism principle have been in extensive use, due to their ease of handling, brightness sufficient for observation purposes, and other advantages. They have normally found their applications in the observation of wild birds, shooting matches and other purposes, because of their reduced weight and ease of operation.
Such ground monocular telescopes operating on the erecting-prism principle have had difficulties in adjusting visibility and field of view in multiple stages, despite their peerless capabilities.
For instance, as is well known, a reticle is mounted in order to determine the distance to a particular object. In the case of the telescope under consideration, it would be impossible to mount a reticle only when it was necessary, and thus it had to be in a mounted state at all times. This resulted in the obstruction by the scales of the reticle to the view of the observer except while a distance was being measured.
These are shortcomings of an erecting-prism type ground monocular telescope which can result inevitably from its advantages. For this reason, in the conventional system, there was nothing which could be done for it but to make the visibility and field-of-view adjustment function exceedingly simple, because a reticle was not free to be mounted or removed, as well as the magnification adjustment could be done only in a single stage.
Accordingly, an erecting-prism type ground telescope incorporating multiple visibility and field-of-view adjustment functions, has been strongly desired.
With the above taken into account, the object of the present invention is to provide a convenient, and easy-to-handle function-conversion device for an erecting-prism type ground monocular telescope, which is designed to overcome the defects from which the conventional equipment has suffered, and to select appropriate levels of visibility and field-of-view.